a1 Stobhill Hospital, Glasgow, UK
a2 School of Psychology, University of Hertfordshire, Hatfield, UK
a3 Benito Menni CASM, Barcelona, Spain
a4 CIBERSAM, Spain
Background Although cognitive behavioural therapy (CBT) is claimed to be effective in schizophrenia, major depression and bipolar disorder, there have been negative findings in well-conducted studies and meta-analyses have not fully considered the potential influence of blindness or the use of control interventions.
Method We pooled data from published trials of CBT in schizophrenia, major depression and bipolar disorder that used controls for non-specific effects of intervention. Trials of effectiveness against relapse were also pooled, including those that compared CBT to treatment as usual (TAU). Blinding was examined as a moderating factor.
Results CBT was not effective in reducing symptoms in schizophrenia or in preventing relapse. CBT was effective in reducing symptoms in major depression, although the effect size was small, and in reducing relapse. CBT was ineffective in reducing relapse in bipolar disorder.
Conclusions CBT is no better than non-specific control interventions in the treatment of schizophrenia and does not reduce relapse rates. It is effective in major depression but the size of the effect is small in treatment studies. On present evidence CBT is not an effective treatment strategy for prevention of relapse in bipolar disorder.
(Received August 20 2008)
(Revised March 11 2009)
(Accepted March 18 2009)
(Online publication May 29 2009)
c1 Address for correspondence: Dr P. J. McKenna, Benito Menni Complex Assistencial en Salut Mental, Germanes Hospitalàries del Sagrat Cor de Jesús, C/Doctor Antoni Pujades 38-C, 08830 Sant Boi de Llobregat, Barcelona, Spain. (Email: email@example.com)